【科学美国人】 已知最古老的壁炉出土于以色列

20140207 Oldest Known Hearth Unearthed in Israel（以色列）

Early humans began using （开始做） fire about a million years ago. But it’s been unclear when we began to control fire for our use, a key advance （进步）in the development of culture and civilization （文明）.

Now, archaeologists report the discovery of the most ancient known hearth for making and using fire. The hearth （炉子）appears to be 300,000 years old.

Scientists found evidence of wood ash in the center of Qesem Cave in Israel. They removed a chunk of sediment and hardened （变硬的）it in the lab, so they could slice （切割）layers （层）and evaluate them under the microscope（显微镜）.

They found burnt （烧过的）bones, flint（打火石）, wood ash （木头灰）and bits （一片片的）of burnt clay （烧黏土）. There’s charred （碳化的）flint and animal bones near the hearth, along with flint tools （打火的工具）further away used for activities such as butchering（屠杀）. The research is in the Journal of Archaeological （考古）Science. [R. Shahack-Gross et al., Evidence for the repeated use of a central hearth at Middle Pleistocene (300 ky ago) Qesem   Cave,Israel]

The investigators （调查者）say the large hearth was used repeatedly over time for a large group of people. Its centralized （中央的）location and division of labor areas suggests （表明了）social structure and spatial（空间的） planning（规划）.

The finding helps delineate （线→描绘）a turning point in human social and cognitive （认知的，心理学考）development. This and other such hearths were crucibles（原始的炉子，不用记） that helped forge （塑造，锻造）modern humanity—and eventually us.

Some weeds are strong enough to resist weed-killing products called herbicides（除草，cid→杀）. But researchers are finding natural ways to deal with unwanted plants（不想要的植物）.